Cyclonic air cleaner assembly

ABSTRACT

An apparatus and method utilize a fan to direct air through a screen to cool an engine. A cyclonic air cleaner assembly receives air from the blower fan and directs the air towards an air-fuel mixing device of the engine.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

The present application claims priority under 35 U.S.0 120 from and is acontinuation of co-pending U.S. patent application Ser. No. 12/259,641filed on by Ryan Sullivan and Gary Johnson and entitled CYCLONIC AIRCLEANER ASSEMBLY which claims priority from U.S. patent application Ser.No. 61/000,790 filed on Oct. 29, 2007 by Ryan Sullivan and Gary Johnsonand entitled CYCLONIC AIR CLEANER ASSEMBLY, the full disclosures ofwhich are hereby incorporated by reference.

BACKGROUND

Typically, cyclonic air cleaning devices are mounted exterior of theengine blower housing and are coupled to a carburetor by way of variousconnection devices. Rain caps are often needed at the air inlet toprevent rain water from entering the cleaning device, andexternally-mounted cleaning devices add bulk to the overall enginepackage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of the blower housing, including the air cleanerassembly.

FIG. 2 is a front view of the air cleaner assembly.

FIG. 3 is a perspective view of the engine package.

FIG. 4 is an exploded view of the blower housing, including the aircleaner assembly.

FIG. 5 is a perspective view of the blower housing, including the aircleaner assembly, with the upper filter housing removed.

FIG. 6 is a bottom view of the air cleaner assembly.

FIG. 7 is a perspective view of the air cleaner assembly including across-section of the air cleaner.

FIG. 8 is a perspective section view of the air cleaner assembly.

DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other embodiments and of being practiced orof being carried out in various ways. Also, it is to be understood thatthe phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting. The use of“including,” “comprising,” or “having” and variations thereof herein ismeant to encompass the items listed thereafter and equivalents thereofas well as additional items. Unless specified or limited otherwise, theterms “mounted,” “connected,” “supported,” and “coupled” and variationsthereof are used broadly and encompass both direct and indirectmountings, connections, supports, and couplings. Further, “connected”and “coupled” are not restricted to physical or mechanical connectionsor couplings.

FIGS. 1 and 2 illustrate the path of air, represented by arrows 12, thatpasses through a blower housing 10, which includes an air cleanerassembly 20. The blower housing 10 also includes a rotating screen 14,which provides a first air inlet for the air cleaner assembly of thepresent invention. The screen 14 is adjacent to an intake portion of acooling fan 16 in a manner well known to those of ordinary skill in theart. This air inlet configuration eliminates the need for a rain capbecause the intake is not directly exposed to the outside environment.

With further reference to FIGS. 1 and 2, and with additional referenceto FIGS. 4 and 5, an air cleaner assembly 20 is disposed within theblower housing 10 and includes an inlet channel 22, an air filter inlet24, a first debris discharge 26, an air filter element 29, a debrissleeve 38, an elbow 48, a lower filter housing 40, an upper filterhousing 46, a scroll 42 and a second debris discharge 32.

The air cleaner inlet channel 22 is disposed adjacent to and receivesintake air from the cooling fan 16, such that at least a portion of airthat has passed through the rotating screen 14 enters the air cleanerassembly 20 by way of the inlet channel 22. A bottom view of the aircleaner assembly 20 in FIG. 6 shows an inlet 56 of inlet channel 22positioned to receive intake air from the flywheel fan 16. An aperturein the inlet channel 22 near a first axial end 34 of the air filterelement forms the air filter inlet 24, although a slot or baffle or anyother opening may be used. The axial end of the inlet channel 22adjacent a second axial end 36 of the air filter element is alsoprovided with an opening, which is the first debris discharge 26. Thecylindrical corrugated filter element 29 is positioned horizontally forspace efficiency, although it may be positioned vertically or in anyother orientation in other constructions. The corrugations of the filterelement 29 are not shown in the figures. An optional foam pre-filter,which is a cylindrical sleeve of foam that surrounds the filter element29, may be included. The debris sleeve 38, best shown in FIG. 5, is acylindrical member coupled to the first axial end 34 of the air filteradjacent the air filter inlet 24. In other constructions, it may be apartial cylindrical member, i.e., an arcuate member. The elbow 48 isconfigured to form a path between the filter element 29 and a carburetorintake 64, best shown in FIG. 7, and is coupled to an axial end of thesleeve 38. In a preferred embodiment, the elbow 48 is generally L-shapedand is formed integrally as one piece with the sleeve 38. However, theelbow 48 may be shaped in any way that directs air from an air filteroutlet 54 to the carburetor intake 64 and may be formed separately fromthe sleeve 38 in another construction.

FIG. 4 shows an exploded view of the air cleaner assembly 20. In apreferred embodiment, the inlet channel 22 is formed integrally as onepiece with the lower filter housing 40. In another construction, theinlet channel 22 and lower filter housing 40 may be separate pieces. Thescroll 42, also preferably formed integrally as one piece with the lowerfilter housing 40, is a wall on the inner surface of the lower filterhousing 40 configured to direct air from the first axial end 34 of thefilter element towards the second axial end 36. The second debrisdischarge 32 is located at the second axial end 36. In a preferredembodiment, the second debris discharge 32 is an aperture configured tobe fitted with a duckbill valve 44. A clip 52 is coupled to the lowerfilter housing 40 to hold the filter element 29 in place. In anotherconstruction, any fastener may be used, such as a clamp, a screw, abale, or a snap-fit between the filter element 29 and the lower filterhousing 40. In yet another construction, no fastener may be neededbetween the filter element 29 and the lower filter housing 40.

FIG. 3 illustrates an air-cooled internal combustion engine 30,including the blower housing 10 and air cleaner assembly 20. The upperfilter housing 46 in the form of a removable cover is shown to havequick-disconnect fasteners 66 (shown as thumbscrews) that provide easyaccess to the air filter element 29 for inspection and replacementthereof. Fastener bosses 62 on the blower shroud 18 corresponding to thequick-disconnect fasteners 66 are shown in FIGS. 4-6. The upper filterhousing 46 is removably fastened to the blower shroud 18 via mechanicalconnection between the quick-disconnect fasteners 66 and the fastenerbosses 62.

The flow path of air through the blower housing 10 and air cleanerassembly 20 is indicated by arrows 12 and 13 in FIGS. 1, 2, 5 and 7. Airis drawn into the blower housing 10 by a flywheel fan or other coolingfan 16 via a rotating screen 14, which provides a first source offiltering upstream of the air filter element 29. At least a portion ofthat air enters the inlet channel 22 via inlet 56. A second source offiltering upstream of the air filter element 29 is provided by the inletchannel 22. The air filter inlet is configured so that air enters thefilter compartment (defined by the lower and upper filter housings 40,46) in a direction substantially normal to the direction of air flowthrough the inlet channel 22. In this way, heavier debris particles areprevented from entering the filter compartment because they are carriedby their momentum straight through the inlet channel 22. An opening atthe end of the inlet channel 22 provides the first debris discharge 26.

As air enters the filter compartment through the air filter inlet 24 ina direction substantially normal to the inlet channel 22, it is firstmet by the sleeve 38 and then the scroll 42, which encourage cyclonicmotion of the air and any remaining entrained debris. In otherconstructions, the sleeve 38 may have grooves or fins or other meansthat encourage cyclonic motion of the air, equivalent to the scroll 42.A centrifugal force imparted by the cyclonic motion of the air anddebris causes the heavier particles (i.e. debris) to migrate towards theinner surfaces of the lower and upper filter housings 40, 46. The debristravels generally cyclonically, or in a helical path, from the firstaxial end 34 to the second axial end 36. In the absence of the sleeve 38and scroll 42, air entering at the air filter inlet 24 could passstraight through the filter element 29. Therefore, it is understood thatother constructions of the sleeve 38 and scroll 42, or combinationsthereof, that prevent the air from passing through the filter near theinlet 24 may exist. In the absence of cyclonic-motion-impartingelements, such as the sleeve 38 and scroll 42, the cyclonic filteringeffect would be compromised because of a reduction in the centrifugalforce acting on the debris.

Debris exits the air cleaner assembly 20 via a second debris discharge32 located adjacent the second axial end 36. The second debris discharge32 is preferably fitted with a duckbill valve 44. As is known to thoseof ordinary skill in the art, duckbill valves are normally closedone-way valves that open when a positive pressure differential existsbetween the upstream and downstream sides of the valve. Other one-wayvalves that would allow the passage of debris only towards the outsideof the air cleaner assembly 20 may be used in other constructions. Lesspreferably, the second debris discharge 32 may have a two-way valve oropening, but this could allow air carrying additional debris to enterthe air cleaner assembly 20. Pressure pulses caused by the internalcombustion engine 30 result in periodic openings of the duckbill valve44 during which debris is discharged from the air cleaner assembly 20.With the separation of debris by way of cyclonic motion and thedischarge of debris, a third form of filtering is achieved.

Air that passes through the filter element 29 is indicated by arrows 13in FIG. 7. The filtered air travels generally axially from the secondaxial end 36 to the first axial end 34 and exits the air filter by wayof an air filter outlet 54. The filtered air travels ultimately to thecarburetor intake 64 via the elbow 48.

FIG. 8 is a perspective view of the air cleaner assembly 20 and blowerhousing 10, wherein the air cleaner assembly 20 is sectionedperpendicular to its axis. The figure also provides a good view of theair filter outlet 54.

An expected advantage of the first and second upstream filtering stepsdescribed above is extended air filter element life. In typical cyclonicair cleaners, grass clippings are not sufficiently prevented fromentering the system. Furthermore, grass clippings are not readilydischarged through any debris discharge passageways due to their shapeand size. As a result, grass clippings tend to accumulate around the airfilter element, inhibiting the cyclonic motion of air. The presentinvention provides a first filtering step upstream of the filter element29 by way of the rotating screen 14, and a second filtering stepupstream of the filter element 29 by way of the configuration of theinlet channel 22. The rotating screen 14 prevents a substantial amountof grass clippings and other debris from entering the system, and theinlet channel 22 encourages any screen-penetrating debris to exit thesystem via the first debris discharge 26. Thus, grass clippings shouldbe prevented from entering the filter compartment. A third filteringstep eliminates most residual debris, which is expected to besubstantially free of grass clippings, by way of the centrifugal forceimparted by the cyclonic motion of air. Finally, the filter element 29provides a final filtering step. As the life of a filter depends on theamount of debris trapped within it, the three filtering steps describedabove are expected to extend the life of the filter by reducing theamount of debris that reaches it.

Additional advantages of the present invention include cost savings. Asthe air cleaner assembly 20 is a part of the blower housing 10, noseparate intake hose or channel is needed. Additionally, no extrabrackets, bolts, or other fasteners are needed to fasten the air cleanerto the housing. The elimination of these parts reduces the overall costof the engine package.

Another advantage of including the air cleaner assembly 20 as a part ofthe blower housing 10 is that the overall bulk of the engine package isreduced.

Although the present disclosure has been described with reference toexample embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the claimed subject matter. For example, although differentexample embodiments may have been described as including one or morefeatures providing one or more benefits, it is contemplated that thedescribed features may be interchanged with one another or alternativelybe combined with one another in the described example embodiments or inother alternative embodiments. Because the technology of the presentdisclosure is relatively complex, not all changes in the technology areforeseeable. The present disclosure described with reference to theexample embodiments and set forth in the following claims is manifestlyintended to be as broad as possible. For example, unless specificallyotherwise noted, the claims reciting a single particular element alsoencompass a plurality of such particular elements.

1. An apparatus comprising: an internal combustion engine having anair-fuel mixing device; a blower fan directing air through a screen tocool the engine; and a cyclonic air cleaner assembly receiving air fromthe blower fan and directing the air towards the air-fuel mixing device;a cylindrical filter; and one or more structures encouraging helicalflow of the air about a cylindrical filter.
 2. The apparatus of claim 1for the comprising a duct having an inlet receiving air from the blowerfan and an outlet through which debris is discharged, wherein thecyclonic air cleaner receives air from the duct between the inlet andthe outlet.
 3. The apparatus of claim 2, wherein the duct extends fromthe inlet to the outlet in a first direction and wherein the cyclonicair cleaner assembly receives air from the duct in a second directionsubstantially perpendicular to the first direction.
 4. The apparatus ofclaim 1 , wherein the cyclonic air cleaner assembly receives air fromthe blower fan proximate the first end of the cylindrical filter andwherein the apparatus further comprises a debris discharge outletproximate an outer circumferential surface of the cylindrical filter anda second end of the cylindrical filter.
 5. The apparatus of claim 4further comprising a one-way valve regulating flow through the debrisdischarge outlet.
 6. The apparatus of claim 5, wherein the one-way valvecomprises a duckbill valve.
 7. The apparatus of claim 1, wherein the oneor more structures comprises a scroll.
 8. The apparatus of claim 7,wherein the one of more structures further comprises a sleeve extendingalong and axial length of the cylindrical filter between the cylindricalfilter and the scroll are located such that the air received from theblower fan enters between the sleeve and the scroll.
 9. The apparatus ofclaim 8 further comprising an airflow duct from an interior of thecylindrical filter to the air-fuel mixing device, wherein the duct isintegrally formed as a single unitary body with the sleeve.
 10. Theapparatus of claim 7 further comprising a housing extending along anexterior of the cylindrical filter, wherein the housing is integrallyformed as a single unitary body with the scroll.
 11. An apparatuscomprising: an internal combustion engine having an air-fuel mixingdevice; a blower fan directing air through a screen to cool the engine;and a cyclonic air cleaner assembly receiving air from the blower fan,directing the air towards the air-fuel mixing device and directingdebris through a one-way valve.
 12. The apparatus of claim 11 for thecomprising a duct having an inlet receiving air from the blower fan andan outlet through which debris is discharged, wherein the cyclonic aircleaner receives air from the duct between the inlet and the outlet. 13.The apparatus of claim 12, wherein the duct extends from the inlet tothe outlet in a first direction and wherein the cyclonic air cleanerassembly receives air from the duct in a second direction substantiallyperpendicular to the first direction.
 14. The apparatus of claim 11,wherein the cyclonic air cleaner assembly comprises: a cylindricalfilter; and one or more structures encouraging helical flow of the airabout a cylindrical filter.
 15. The apparatus of claim 14, wherein thecyclonic air cleaner assembly receives air from the blower fan proximatethe first end of the cylindrical filter and wherein the debris dischargeoutlet is proximate an outer circumferential surface of the cylindricalfilter at a second end of the cylindrical filter.
 16. The apparatus ofclaim 14, wherein the one or more structures comprises a scroll.
 17. Theapparatus of claim 16, wherein the one of more structures furthercomprises a sleeve extending along and axial length of the cylindricalfilter between the cylindrical filter and the scroll are located suchthat the air received from the blower fan enters between the sleeve andthe scroll.
 18. The apparatus of claim 17 further comprising an airflowduct from an interior of the cylindrical filter to the carburetor,wherein the duct is integrally formed as a single unitary body with thesleeve.
 19. The apparatus of claim 16 further comprising a housingextending along an exterior of the cylindrical filter, wherein thehousing is integrally formed as a single unitary body with the scroll.20. The apparatus of claim 11, wherein the one-way valve comprises aduckbill valve.
 21. The apparatus of claim 11, wherein the air-fuelmixing device comprises a carburetor.
 22. A method comprising: drawingair through a screen with a fan; directing a first portion of the airdrawn through the screen to cool an internal combustion engine;directing a second portion of the air drawn through the screen to acyclonic air cleaner assembly; directing air from the cyclonic aircleaner assembly to an air-fuel mixing device of the internal combustionengine; and directing debris from the cyclonic air cleaner assemblythrough a one-way valve.
 23. The method of claim 22 further comprisingdirecting the second portion of air through an inlet of a duct having afirst debris discharge outlet, wherein the second portion of air entersthe cyclonic air cleaner assembly between the inlet and the outlet. 24.The method of claim 23, wherein the duct extends in the first directionfrom the inlet to the outlet and wherein the method further comprisesdirecting a second portion of air from the duct into the cyclonic aircleaner assembly in a second direction substantially perpendicular tothe first direction.
 25. The method of claim 23, wherein the cyclonicair cleaner assembly includes a filter and wherein the method furthercomprises helically directing the second portion of air about thefilter.
 26. The method of claim 25, wherein the filter is cylindricaland wherein filtered air within an interior of the filter is directed tothe carburetor.
 27. The method of claim 25, wherein the filter has afirst end and a second and, wherein the second portion of air enters thecyclonic air cleaner assembly proximate the first end and wherein themethod further comprises discharging debris through a second debrisdischarge outlet proximate the second end.